1. Field of the Invention
The present invention relates to an optical device and the packaging method thereof, especially to an optical sub-assembly and the packaging method thereof.
2. Description of Related Art
In recent years, as the demand for data throughput and transmission speed goes up, the traditional way in using copper cables as the data transmission medium is gradually out of date; therefore fiber transmission has taken the place of copper transmission to be the major medium for high speed transmission step by step. However, in comparison with an electric transceiver module applicable to cooper transmission, an optical transceiver module applicable to fiber transmission is relatively expensive. One reason of the high cost is that the optical transceiver module adopts the active alignment process of optical coupling which consumes a lot effort and time; more specifically, said active alignment process has to adjust the position relationship between a fiber and an optical transceiver in multi-axial directions, so as to find out the optimal positions of these components for achieving the best coupling efficiency. Although such active alignment process can reach high optical coupling efficiency, it also consumes much time and cost. On the other hand, the aforementioned optical transceiver module can adopt passive alignment process instead; however, the known passive alignment process has to use etching technique of extremely high cost to etch a substrate for making a V-shape slot on it, so that an optical transceiver and a fiber could be set on the substrate and the V-shape slot respectively to accomplish the position arrangement which is simple but imprecise. Accordingly, in consideration the low position precision and costly etching step, said passive alignment process is not a good option, either.
In addition to the above, the mentioned active alignment process further possess the disadvantages of low design tolerance and being easily affected by heat, shake or shock. Moreover, the well-known TO-CAN (Transistor Outline-Can) type, dual in line type, and butterfly type of optical sub-assembly module all adopt the active alignment process of optical coupling, and consequently inherit the same shortcomings described above.
Therefore, the coupling efficiency and production yield of the current optical transceiver module still have a long way to go. Since the current arts are not good enough and the demand for optical transmission obviously increases, a cost effective, packaging-efficient, and optical-coupling excellent solution is thus greatly expected.